The present invention relates to a device for guiding a cable set arranged at a manipulator equipped with a control device where the cable set forms a slack in the transition between a first and second manipulator part joined by a link-including a guiding device that freely surrounds the cable set.
It is known that industrial robots have both power and signal cables drawn internally in the robot. This results, among other things, in a cable set being protected from damage that can occur during operation. In industrial robots where the cable set runs free and is unprotected in the transition between the foot of the robot and the under arm or, alternatively, between two robot arm parts, there is a risk that it may get jammed in other parts of the robot. This problem is particularly acute when a freely hanging part of the cable, arranged to allow movements of the robot, forms an external loop known as a slack. This can entail that the cable set can come into contact with other moving parts of the robot. In the Japanese document JP,A, 09309091, the problem has been solved in the following way. In an industrial robot including a foot, under arm and upper arm that are joined to pivot, the motors that drive the pivoting movement of the under arm respective upper arm are arranged on the foot to be coaxial with the pivoting axis of the under arm (FIG. 5). The design provides an empty space between the driving of the lower and upper robot arms respectively. A coupling axle with a hole running through it at right angles to its longitudinal axis is arranged in the said space in the link. The coupling axle is jointed to rotate at one of its ends and to be firmly attached or, alternatively, to rotate at the other end. The aim of the coupling axle provided with the hole is to counteract the occurrence of slack between two sides in an under arm without reducing the positioning accuracy. The radius of the bending of the cable set within the robot can be made larger and the risk for breaks in the cable is reduced. In addition, the restriction on the degree of rotation of the underarm caused by the cable set inside the robot is eliminated.
Problems arise when one needs to add to the cable set of the industrial robot. Normally, cable sets for robots are manufactured complete with ready-mounted connecting means in the form of, for example, contact plates or contact means. When a ready-made line is to be fitted in an existing robot, there is too little space for the line to be drawn in through the coupling axle. When additions are to be made to an industrial robot according to the Japanese document, one of the connecting means must be removed at the end of the line or, alternatively, the lines are delivered with the coupling axle already attached. In the latter case, a considerable job of assembly must be performed before the new line and coupling axle are in place.
When working with industrial robots, therefore, the need thus arises for a guiding device for the cable set where the device guides a slack and also makes it easy to add extra lines to the cable set. This need cannot be met by the industrial robot in the Japanese document.
During manufacture, industrial robots are equipped with manipulators-cable sets for driving the robot. They are also provided with so-called customer signals that include the drive cables that the operator/customer needs for their application. The aim of the development of power supplies to robots is to create a flexible system for both the robot manufacturer and the customer. In a flexible system, the robot manufacturer can produce a standard concept. The customer then decides how the robot is to be equipped prior to delivery. Afterwards, a flexible system gives the users/customers themselves the opportunity to decide and equip the robot with the equipment for the functions they require. A flexible system also gives the user the possibility to completely change the functional equipment of the robot so that the robot can be used for totally different tasks during its working life.
The object of the present invention is thus to achieve a device with which one can guide slack and at the same time allow additions to be made to the cable set in a simple manner.